Improvement in relief-valves for steam air-brake cylinders



GEORGE wEsTlNGH'ousE, n. Improvement in Relief Valves for SteamAir Brake Cylinders. 910,124,403, l PatenfedMarchsnan.

UNITED STATES GEORGE WESTINGHOUSE, JR., OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN RELIEF-VALVES FOR STEAM AIR-BRAKE CYLINDERS.

Specification forming part of Letters Patent No. 124,403, dated March 5, 1872.

To all whom lit may concern:

Be it known that I, GEORGE WEs'rrNG- HOUSE, Jr., of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Itelief-Valve for Steam-Power Air-Brake Cylinders; and I do hereby declare the following to be a full, clear, and exact description thereof,reference being had to the accompanying drawing making a part of this speciiication, in which-' Figure 1 is a plan view, partly in section, of my improved apparatus; and Fig. 2 is a sectional view through :n a', Fig. l.

My invention relates to the construction and combination of devices appertainin g to steampower air-brake apparatus, and more particularly designed for letting the air escape suddenly and rapidly-from the brake-cylinder, so that the brakes shall be let Oft' with equal suddenness and rapidity.

To enable others skilled in the art to make and use my improvement, I will proceed to describe its construction and mode of operation.

The pipe a extends through the train, and communicates at its forward end with the compressed-air reservoir or other device for generating or storing air-pressure. Under each car is arranged the usual brake-cylinder b. The air-pipe a and brake-cylinder b are connected together by the pipes c, c1, and d. The pipe d is tted with a check-valve, d', of the usual or any known construction, such that when the compressed air is admitted or forced into thc pipe a it will be free to flow through the check-valve d into the cylinder b, and apply the brakes in the usual way; but as soon as the engineer turns 4the cock to allow the air to escape from the pipe a the back pressure of air from the cylinder b will seat the valve d', and close all communication. To provide for the escape of theair from the cylinder b I make use ofthe pipes c 01. The pipe c has at its outer end a valve-case, c2, containing a chamber larger at one end, e, than at the other, e. The pipe o1 opens into this valvechamber at or about midway between itse'nds.

The chamber e e contains the valves g g1, at'- Xed to a common stem, g2, the distance between the outer faces of the valves g g1 being somewhat less than the length of the' valvechamber e e', and the valve g being the larger Of the two, and of about the same diameter as its part of the chamber e. The smaller valve g1 is somewhat less in diameter than its part e of the chamber, and has guides or wings s, through or between which the air may pass in escaping. The Outer 'end of the valve-case c2 is open at c3.

It will now be Obvious that, when the compressed air is turned on, not only will it flow through the pipe d into the brake-cylii'ider, as already described, but also it will, passing into the pipe c, press against the outer face of the valve g, and seat the valve g1 on its elastic seat t', and thus close the escape c3, and

keep it closed 5 and as soon as air is allowedto escape from the pipe a sufficiently to lessen the pressure therein, not only will the checkvalve d be seated, as already described7 but also the pressure ofl the air 'in the cylinder b, acting through the pipe o1, will act against the inner face ofthe valve g; and since its area is greater than that of the valve g1, it (thevalve g) will be thrown over to its seat o, thus closing the pipe c, and lifting the valve g1 from its seat, so as tO open the escape'c. v'Ihe air is then free to escape from the cylinder b, iowing out between the wings s. The brakes are thus let oftl almost instantly7 andthe train is ready for a start.

What I claim as my invention, and desire to secure by Letters Patent, is

The double valve device g g1 g2 as a reliefvalve for the cylinder b, when combined with a check-valve, d', arranged with pipe-connections, substantially as described.

In testimony whereof, I, the said GEORGE WESTINGHOUSE, Jr., have hereunto set my hand.

GEO. WESTINGHOUSE, JR.

Witnesses:

A. S. NICHOLSON, G. H. CHRISTY. 

